Hundreds have died of heat exhaustion in the U.K. this summer. Pavement buckled across the eastern and central U.S. where a heat wave is broiling 21 states. Australia set new record high temperatures in their most recent summer. Anyone born after February 1985 has never lived through a month that was cooler than the 20th century’s global average.

Of course, A-C eats a lot of energy. Cooling accounts for fully 40 percent of the electricity demand of a typical U.S. building. Which means our coolness relies on fossil fuel burning that ups CO2 pollution and warms the planet. To compound the problem, the liquids used for all this comfort—first chlorofluorocarbons and now hydrofluorocarbons—are super-strength greenhouse gases.

As A-C use spreads, cooling technology must become more environmentally-friendly and energy efficient. Otherwise, there’ll be no place to hide from the heat.